Remote sensing-based monitoring and assessment of the geological environment of the Chagan'aobao iron-zinc mine in East Ujimqin Banner, Inner Mongolia

Remote sensing-based, long time-series monitoring and geological environment assessment of individual mines enable the analysis of variations in their land damage and ecological restoration. These efforts are fundamental for the engineering design of ecological restoration in underground mines and for achieving mine-specific solutions. This study investigated the Chagan'aobao iron-zinc mine in East Ujimqin Banner, Inner Mongolia. The 17-phase remote sensing data reveal that mining activities in the mine damaged 59.47 hm² of land by 2008, which expanded to 158.29 hm² by 2024, with the damaged land area peaking at 165.21 hm² in 2022. Appropriate control of the scale of collapse pits and prompt ecological restoration can effectively curb the expansion of land areas damaged by mining. By integrating 13 factors, including lithologic associations and slope structures, a remote sensing-based assessment model for the geological environments of a single mine was constructed, allowing for the effective identification of the degree of impacts on a mine's geological environment. Within the region, the areas classified as general, moderate, and severe mining-affected zones covered areas of 32.34 hm², 132.37 hm², and 7.15 hm², respectively. For severe mining-affected zones like collapse pits, it is recommended to implement engineering measures, including both slope cutting for unloading and footing placement at pit bottoms, to mitigate geological hazard risks. Meanwhile, soil reconstitution and vegetation restoration should be temporarily deferred. For moderate mining-affected zones, including tailings ponds and mining industrial sites, it is necessary to monitor regional subsidence impacts and enhance routine inspections. Additionally, ecological restoration measures, such as soil covering and grass planting, can be deployed for general mining-affected zones.